Study seeks to extend life of concrete structures using bacteria

Cowi is field-testing new technology that uses bacteria to fight concrete’s arch-enemies, water and chemicals.

The technique is designed to extend the life of structures by mixing limestone-producing bacteria with the concrete.

The work is being carried out under a new research project financed by the EU and led by the University of Ghent in Belgium. By adding an endolithic bacteria, which can live inside stone, to the concrete mix the Healcon project is aimed at increasing the life of marine structures in particular.

Cowi will be leading the project's end-user board and will perform life-cycle cost analysis to make sure the relevant industries get maximum benefit from the project.

Heading this work will be Cowi's resident concrete expert, Carola Edvardsen of the department for tunnels. She started researching self-healing of concrete 20 years ago. "It is much like the bones of the human body, really, where broken bones heal themselves over time. As the water seeps into the concrete, the bacteria will activate and start producing limestone which will mend the cracks before they become a threat to the structure," she said.

"Despite extensive lab research we still don't know enough about how it will work in actual practice," she said. The main unknown is for how long the bacteria can survive inside the concrete, but all data points in the same direction: this is going to work."

She said that the project is expected to cut maintenance costs by up to 2%, which in the EU alone adds up to more than €100m (£83m) each year.